Diverse joining techniques are used to join an optical module, such as an objective lens, to a support casing, such as an objective lens holder or a camera body, wherein the quality of cameras decisively depends on the quality of the joints between the optical module and the support casing and results from, inter alia, camera-intrinsic tolerances and mounting tolerances. Aside from that, positional tolerances, in particular the roll, yaw and pitch angles of, e.g., the objective lens in the support casing, considerably influence the functionality of a camera. In addition, a very good and long-time stable alignment of the optical module relative to the support casing is generally necessary regardless of the joining technique used.
An arrangement in which an objective lens holder is joined to a printed circuit board, such as a flexible printed circuit board, is often used to position an objective lens above an image recording element. An image recording element, such as an image sensor (imager), is arranged on the printed circuit board, wherein the printed circuit board itself is fixed to a supporting plate, wherein the image recording element is usually soldered to the printed circuit board. Alternatively, the image recording element is directly adhesively bonded to the printed circuit board using the chip-on-board technology and contacting is performed by means of bonds.
A disadvantage of the above-described optical devices for positioning an optical module above an image recording element consists in the fact that shrinkage occurring during the curing of the adhesive has a direct effect on the focusing of the optical device. Furthermore, a disadvantage of the arrangement consisting of the image recording element, the printed circuit board and the supporting plate, i.e., of the arrangement in which the image recording element is arranged above the printed circuit board and the printed circuit board is arranged above the supporting plate, consists in the fact that influences of the printed circuit board, such as tolerances, thermal behavior and aging, also have an effect on the focusing of the optical device since the optical module (objective lens) is directly joined to the printed circuit board by means of the objective lens holder. Aside from that, it is difficult to directly adhesively bond elements (such as an objective lens holder) to, e.g., a flexible printed circuit board as is the case with known devices.
Furthermore, a disadvantage of other known devices for aligning and joining an optical module above an image recording element consists in the fact that the design of the camera with many individual components is often complicated, which results in an increased manufacturing effort on account of complex components used in manufacturing.